A semiconductor light-emitting device which uses a nitride semiconductor such as GaN is capable of emitting ultraviolet light or blue light, and is also capable of emitting white light when using phosphors (for example, Japanese Laid-open Patent Publications No. 2011-119734 and No. 2013-501350). Such a semiconductor light-emitting device can be used for lighting tools and more specifically lighting tools for a vehicle or the like.
Recently, a technology for a vehicle headlamp has been focused in which a light distribution shape is controlled in real time depending on circumstances in front of a vehicle, that is, the presence/absence of oncoming vehicles, vehicles ahead, or the like and positions thereof. Such a technology is generally referred to as adaptive driving beam (ADB), adaptive front lighting system (AFS), or the like. In the ADB or AFS, for example, a plurality of semiconductor light-emitting devices which are capable of independently performing on/off control are used.